/** Install Semantic Highlighting on the previewer */
 private void installSemanticHighlighting() {
   if (fSemanticHighlightingManager == null) {
     fSemanticHighlightingManager = new SemanticHighlightingManager();
     fSemanticHighlightingManager.install(
         fPreviewViewer, fColorManager, getPreferenceStore(), createPreviewerRanges());
   }
 }
 /** Uninstall Semantic Highlighting from the previewer */
 private void uninstallSemanticHighlighting() {
   if (fSemanticHighlightingManager != null) {
     fSemanticHighlightingManager.uninstall();
     fSemanticHighlightingManager = null;
   }
 }